Arthropods such as termites, carpenter ants, fire ants and roaches have been a common nuisance pest. In southern regions especially Florida, termites are considered to be one of the most destructive arthropod pests for structures. The two forms of subterranean termites that are of concern for pest control are subterranean termites, which typically nest in the ground and usually maintain some sort of ground connection, and drywood termites, which start as a pair in a piece of wood and do not have a ground connection. Subterranean termites are the most damaging termites and usually enter buildings from the surrounding soil.
Over the years there have been at least several methods of subterranean termite control. For example, the most common method of subterranean termite control requires soil underlying a structure to be treated with a termiticide barrier (usually hundreds of gallons of termiticide per house) to prevent termites from entering the structure from the ground. From 1950 to 1988 chlorinated hydrocarbons were the main method of barrier treatment to control subterranean termites. However, environmental concerns with those chemical treatments resulted in the loss of chlorinated hydrocarbons that lasted up to 35 years in the soil. Chemicals that replaced the chlorinated hydrocarbons for barrier treatment have had a high rate of failure resulting in extensive termite damage to structures.
Problems with the barrier treatments become further compounded since builders have often been known to dump substantial amounts of edible building materials, such as wood and cardboard into the underlying soil that can serve as guidelines into the structures and provide a substantial food source, increasing the probability of termite infestation in the structure.
Over the years, different techniques and systems have also been proposed to enhance the underground delivery of toxic insecticides beneath structures. See for example, U.S. Pat. Nos. 3,940,875 and 4,043,073 to Basile; and U.S. Pat. No. 4,625,474 to Peacock. However, many of these techniques and systems such as Basile ""073 are concerned with trying to refresh the initial termiticide barrier by having the termites chew through a container with the toxicant (for example. Other examples of these techniques and systems allow for installing a piping system during the building construction process so that additional termiticide can be pumped under a slab of the building at intervals after construction. Furthermore, some of these techniques and systems such as the Basile ""073 patent utilized a toxicant (for example, dieldrin) that has been banned by the EPA(Environmental Protection Agency) for termite treatment. Additionally, the pipe delivery systems have been known to often got clogged after installation making the pipe delivery systems not usable.
Still other well-known subterranean termite treatment techniques and systems include bait techniques, which require termites to forage into a monitor that contains a non-toxic food source. Once termites infest the non-toxic food source, a food source laced with a toxicant (toxic bait) is replaced into the monitor. Termites continue to recruit to the monitor and feed on the toxic bait. Consumption and trophallaxis (feeding other termites) of the toxic bait later causes many termites to die. See for example, U.S. Pat. No. 5,329,726 to Thome et al.; U.S. Pat. No. 5,899,018 to Gordon et al.; and U.S. Pat. No. 5,950,356 to Nimocks. However, these techniques generally require that the termites consume the toxic bait. Termites refuse to consume most toxicants; therefore this technique is useful for only 2-3 toxicants currently known in the world. Termites also refuse to consume bait food sources that are contaminated with molds or are too wet. These bait techniques do not use a non-edible foraging matrix (described in the subject invention), such as soil and sand, to cause the termites to tunnel therethrough and carry the non-edible particles treated with toxicant to the galleries and living spaces of the colony; thus contaminating them. Most toxicants applied to non-edible foraging matrix, except the repellent pyrethroids, will be picked up and carried by termites to other areas of their tunnel system.
Other systems have been proposed but still fail to overcome the problems with the methods and applications described for the cited patents above. U.S. Pat. No. 3,972,993 to Kobayashi et al. requires a membrane treated with a substance attractive to termites (due to the termite""s innate searching and feeding behavior, termites are not attracted to food from a distance when allowed to forage without interference) so that when the termites chew through the membrane a toxic surface is contacted. U.S. Pat. No. 5,501,033 to Wefler delivers a liquid toxic food source for social insects like yellowjackets and has very little use for termites. U.S. Pat. No. 5,609,879 to Myles requires the laborious harvesting of termites from the ground, sponging on an insecticidal epoxy, and returning them to the soil. U.S. Pat. No. 5,778,596 to Henderson et al. is a device for delivering toxic food for termites to consume. And U.S. Pat. No. 5,921,018 to Hirose provides foraging guidelines for termites to follow so they enter a device that captures and kills them.
There are additional problems with prior art treatments that use repellent liquids, non-repellent liquids, and baits. When using repellent liquids, the liquid barriers need to be applied in a perfectly continuous fashion. If gaps in the treatment exist, especially with repellent termiticides, such as those belonging to the pyrethroid class, the termites will forage and find the gaps in the treatment, increasing the probability of infesting the structure.
In non-repellent liquid treatments, the termites are not able to detect that they are in a treated area; hence the classification xe2x80x9cnon-repellent,xe2x80x9d and they die. A major drawback for non-repellant liquid treatments is that liquid termiticides in this class are still so new that there are questions about how long they will last in the soil, especially when exposed to sun and weather. The present invention protects the foraging matrix from sun and weather to prolong its usability, and the foraging matrix can be continuously replaced as necessary to recharge the system. The application of liquid termiticide barriers requires several hundred gallons of insecticide that are pumped under houses, sometimes resulting in contamination of the house interior and water supply wells. Most homeowners want applications that are less intrusive and disruptive.
Bait type station techniques and systems are again not practical since the bait stations require a food source that is palatable to termites. Selecting the appropriate food source can be difficult. While wood is a known food source, wood is very inconsistent in composition, so manufacturers don""t like to use it for use with toxicants. Other known food sources such as paper food sources have other problems. For example, if paper is not packed tightly enough, it will be emptied by termites and not deliver enough toxicant to kill large numbers of termites. Most cellulose material will rot when placed in the soil. Once the food goes bad, termites will not feed, rendering the bait ineffective.
The subject invention uses a non-edible foraging matrix treated with a slow-acting non-repellent toxicant. Termites put the particles of the treated matrix into their mouths when they tunnel through it, and many toxicants will work because they do not need to consume it and feed it to others. The particles are returned to the colony and incorporated into their tunnels. Termites that contact the particles die several days after the toxicant on the matrix particles are contacted. The behavior of the termites moves the treated foraging matrix from the exit and entrance opening of the device""s chamber to contaminate their colony and tunnels.
The first objective of the present invention is to provide a method and system for killing arthropods such as termites, carpenter ants, fire ants and roaches over time and protecting structures.
The second objective of this invention is to provide a method and system for destroying arthropods such as termites, carpenter ants, fire ants and roaches using a non-toxic and edible food source to attract the arthropods and only causing the arthropods to tunnel through non-edible particles treated with a slow-acting and non-repellant toxicant when the arthropods return to their colonies so that the arthropods contaminate their galleries and living spaces with the particles.
The third objective of this invention is to use soil particles, sand particles, mixtures or other non-edible foraging matrices as a method of dispersing the toxicant to -arthropods such as termites, carpenter ants, fire ants and roaches that pass through tunnels, galleries, and living spaces.
The fourth objective of this invention is to use various housings that can be inserted into the ground for treating arthropods such as termites, carpenter ants, fire ants and roaches.
Preferred embodiments of the method and apparatus of killing arthropods such as termites, carpenter ants, fire ants and roaches and protecting structures. The method includes the steps of: inserting a nontoxic food source such as wood, paper, cardboard, and cellulose-based material, into a chamber, positioning the chamber adjacent to arthropods and allowing the arthropods to enter and eat the nontoxic food source, inserting a foraging non-edible matrix treated with a slow acting and non-repellent toxicant into the chamber so that the foraging matrix is between the non-toxic food sources, and allowing the arthropods to exit from the chamber, wherein the slow acting and non-repellent toxicant destroys the arthropods in their colonies over time and protects structures.
The chamber can be sandwich shaped, cylindrical shaped, disc shaped and the like. The chamber can include a removable cap so the chamber can be serviced through time, and/or include narrow tip stake bottoms for allowing easy insertion when being pushed into the ground.
The chambers can be substantially composed of materials that will naturally decompose over time such as wood and cellulose, and the like. Alternatively, the outer walls of the chambers can include an outer frame formed from a long lasting material such as rust resistant metal, aluminum, plastics, and the like, having openings therethrough, so that interior chambers containing the mixtures of the non-edible foraging matrix and slow-acting toxins can be changed, substituted, replenished over time.
The non-edible foraging matrix can be chosen from soil, sand, gravel, rocks, pebbles, shale, combinations thereof, and the like. The non-edible foraging matrix can be poured into the chamber or be separated inserted into another chamber that can be put into the first chamber.
Toxicants suitable for use are slow acting, non-repellant toxicants for control of arthropods such as termites, carpenter ants, fire ants and roaches. For termite applications, these toxicants can include but are not limited to for example chlorinated nicotine derivatives such as fipronil and imidachoprid; organophosphates such as chlorpyrifos; pyrroles such as chlorfenapyr. A preferred embodiment of the slow acting and non-repellent toxicant can include approximately 1.25 ppm to approximately 12.5 ppm of fipronil. The slow acting and non-repellent toxicant can o also include approximately 2.5 ppm to approximately 25 ppm of chlorfenapyr. The slow acting and non-repellent toxicant can also include approximately 0.5 ppm to approximately 50 ppm of imidacloprid. The slow acting and non-repellent toxicant can also include approximately 0.5 to approximately 50 ppm of chlorpyrifos or other toxicants that is not repellent to the termites.
Still further applications can include multiple layers of mixtures of non-edible foraging matrix and slow-acting toxins, and edible type materials such as cellulose and Styrofoam that allows different types of arthropods such as termites and fire ants and carpenter ants to be treated with the same device.